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author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-08 00:40:47 +0000 |
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committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-08 00:40:47 +0000 |
commit | 130e603115129ec1a6b94550a15f7caea0cbf068 (patch) | |
tree | 28a4c8203a80b25ffb5d0209708f6afbbc6a2a6f /lib | |
parent | 5e63d43e48f6d0b597d21b83a1eed9eaf2febc93 (diff) | |
download | external_llvm-130e603115129ec1a6b94550a15f7caea0cbf068.zip external_llvm-130e603115129ec1a6b94550a15f7caea0cbf068.tar.gz external_llvm-130e603115129ec1a6b94550a15f7caea0cbf068.tar.bz2 |
Don't scan physreg use-def chains looking for a PIC base.
We can't rematerialize a PIC base after register allocation anyway, and
scanning physreg use-def chains is very expensive in a function with
many calls.
<rdar://problem/12047515>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161461 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index ec793f8..b26c08f 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -1463,6 +1463,9 @@ unsigned X86InstrInfo::isStoreToStackSlotPostFE(const MachineInstr *MI, /// regIsPICBase - Return true if register is PIC base (i.e.g defined by /// X86::MOVPC32r. static bool regIsPICBase(unsigned BaseReg, const MachineRegisterInfo &MRI) { + // Don't waste compile time scanning use-def chains of physregs. + if (!TargetRegisterInfo::isVirtualRegister(BaseReg)) + return false; bool isPICBase = false; for (MachineRegisterInfo::def_iterator I = MRI.def_begin(BaseReg), E = MRI.def_end(); I != E; ++I) { @@ -1520,16 +1523,7 @@ X86InstrInfo::isReallyTriviallyReMaterializable(const MachineInstr *MI, return false; const MachineFunction &MF = *MI->getParent()->getParent(); const MachineRegisterInfo &MRI = MF.getRegInfo(); - bool isPICBase = false; - for (MachineRegisterInfo::def_iterator I = MRI.def_begin(BaseReg), - E = MRI.def_end(); I != E; ++I) { - MachineInstr *DefMI = I.getOperand().getParent(); - if (DefMI->getOpcode() != X86::MOVPC32r) - return false; - assert(!isPICBase && "More than one PIC base?"); - isPICBase = true; - } - return isPICBase; + return regIsPICBase(BaseReg, MRI); } return false; } |